This reverts commit 2908fc0d3f16f873b5019f1c62a24482c2b75e36.
Use irbuilder as default and remove redundant Clang codegen for masked construct and master construct. Reviewed By: jdoerfert Differential Revision: https://reviews.llvm.org/D100874
Reviewed By: ABataev Differential Revision: https://reviews.llvm.org/D100514